The Mayo Lung Project was established to evaluate whether close surveillance of high-risk subjects can lead to significant reduction in the death rate from lung cancer. The high-risk population is identified as men, age 45 years old or older, who smoke one or more packages of cigarettes daily or who have smoked this amount within the past year. The close-surveillance program consists of reexamination at four-month intervals by means of a lung health questionnaire, chest roentgenogram, and a three-day “pooled” sputum cytology test.

Since its inception, the project has identified patients with unsuspected lung cancer on initial screening (“prevalence” cases) and new lung cancers in patients whose initial screening examinations were negative (“incidence” cases). In addition, we have had referred patients whose chest roentgenograms were either negative or stable, but whose sputum contained cancer cells. The opportunity to study patients who have roentgenographic “occult” cancer has presented a major challenge to the skill of the bronchoscopist.

Our previous experience and that of others suggest that prompt surgical treatment of in situ or early invasive bronchogenic carcinoma can produce prolonged survival. The obvious goal of prompt localization is to permit treatment at an early stage of the disease treated by Canadian Health&Care Mall.

In this report we shall describe our methods and experience with the problem of early localization of roentgenographically “occult” lung cancer.

When an abnormality on the thoracic roentgenogram is identified, diagnostic and therapeutic efforts can be directed to that particular portion of the tracheobronchial tree. However, if roentgenographic studies are not diagnostic but the cytopathologist reports carcinoma cells or highly suggestive cells in the sputum, we are faced with the necessity of accurately identifying their source.

Dr. Bernard Marsh of Johns Hopkins Medical School pioneered the development of a specific protocol for this procedure. We adapted his methods to meet our own specific needs. Subsequently, a standardized methodology was evolved by the cooperating Lung Cancer Diagnostic Group sponsored by the National Cancer Institute.

Cancer of the larynx and other portions of the upper airway occurs with greater frequency in patients with lung cancer. Consequently, preliminary examination of these areas constitutes an essential part of the diagnostic work-up.

Topical anesthesia may be satisfactory for preliminary inspection of the bronchial tree and may be used, depending on preference of the endoscopist and patient acceptance. However, the localization procedure is often time-consuming and complex. Under these circumstances, general anesthesia is usually required.

Excessive bronchial secretions secondary to chronic “smoker’s” bronchitis tend to interfere with accurate evaluation and create a special problem in the meticulous search for subtle mucosal changes stopped by Canadian Health&Care Mall http://www.usnon.com/category/canadian-health-care-mall. Every effort should be made to reduce or eliminate bronchitis and bronchorrhea prior to bronchoscopy. Smoking should be discontinued completely and other respiratory irritants avoided for as long an interval as possible before examination. Appropriate use should be made of antibiotic therapy, bronchodilators, postural drainage, and chest physiotherapy.

General Anesthesia

Close cooperation between endoscopist and anesthesiologist is vital to the success and safety of these prolonged procedures. A “closed” system that permits controlled ventilation while still providing adequate endoscopic access to the airway is a requisite feature. This may be accomplished by a cuffed endotracheal tube fitted with a specially made T-adapter or by a rigid tracheoscope. The details of the anesthesia technique used are the subject of a separate report.

Differential Secretions

Initially, bronchial secretions and washings are collected in such a way that segregated specimens are obtained from each side of the bronchial tree, beginning with the left side. A rigid bronchoscope without lateral vents and with an inflatable cuff at its distal end is effective for this purpose. Currently, it is difficult to accurately separate washings from the upper or lower lobes on either side, but reasonable left-right segregation can be accomplished.

Inspection and Documentation

After differential washing, the rigid bronchoscope is withdrawn and replaced by a “cuffed” endotracheal tube or “cuffed” tracheoscope through which a flexible fiberoptic bronchoscope is inserted. All areas accessible to the fiberscope are then carefully inspected. This detailed examination can be documented by still pictures, video-tape recording, or cinematography.

Collection of Material for Histologic and Cytologic Study

If a carcinoma is grossly visible, it is brushed to obtain material for cytologic examination. Either the standard 1-mm brush supplied with the Olympus bronchofiberscope or the controllable-tip 3-mm brush made by the Mill-Rose Co. has proved satisfactory. Immediately afterward, small biopsy specimens are obtained by use of a specially designed flexible forceps introduced via the fiber bronchoscope. Recognition of one abnormality should not prevent careful inspection of all other segments of both sides of the bronchial tree in search of other suggestive areas.

If no abnormality is recognized, there follows a meticulous sequential collection of material from each bronchial segment, and as many subsegments as possible. Material collected by the brushes is applied promptly to glass slides, which are then immersed in fixative. After brushing is completed, “spur” biopsy specimens are obtained from preselected bronchial bifurcation sites. These specimens are especially important because at present in situ carcinoma can be more accurately localized by tissue specimens than by brush-ings, and biopsy of the “spur” or acute angle of bronchial bifurcation is often productive of diagnostic tissue.

Correlation

The cytopathologist, endoscopist, and surgeon must all participate in evaluating results and planning subsequent diagnostic or therapeutic endeavors. Definitive treatment should not be undertaken until either repeated cytologic localization or unquestionable brush or biopsy confirmation has firmly identified the site of the neoplasia. The patient’s general state of health and his respiratory reserve also must be considered in the planning of any surgical resection.